Terminal for resistors



TERMINAL FOR RESISTORS 3118:: Oct. 28, 1922 PIS: a 9

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WITNESSES: n INVENTOR d Howard A. Hands.

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ATTORNEY Patented May 11, 192..

insan rarest series.

HOWARD A. HANDS, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOB, TO ESTING- HOIJ'SE ELEOTRZC 85' MANUFACTURING COMPANY, A CORPORATION OF PENN- SYLVANIA.

TERMINAL FOR RESISTORS.

Application filed October 28, 1922.

My invention relates to terminals and particularly to terminals for resistor elements used in heating furnace and appliances.

One object of my invention is to provide a resistor-terminal device wherein the terminal of the resistor is securely fastened to the terminal of the furnace in such manner as to provide an extensive area. of contact and wherein surfaces of the resistor in contact with the furnace terminal are protected from the gases and high temperatures prevailing within the furnace.

Another object of my invention is to provide a simple terminal device wherein standard bolts and nuts may be used for securing a resistor terminal to a furnace terminal.

Another object of my invention is to provide a terminal device for resistors wherein the resistor may be attached to, and removed from, the furnace terminal with a minimum of effort and wherein a durable connection between the resistor terminal and the furnace terminal is obtained.

These and other objects, that will he made apparent throughout the further description of my invention, are attained by means of the apparatus hereinafter described, and illlustrated in the accompanying drawings, wherein:

Figure 1 is a View, partially in section and partially in elevation, showing the terninal device with one of the parts in disassembled relation;

Fig. 2 is a view similar to that shown in Fig. 1, with the parts in assembled relation, and

Fig. 8 is an elevational View of the terminal of the resistor element.

Referring to the drawings, a furnace terminal 4 is shown having an opening 5 through which a threaded bolt 6 projects. The resistor or heating element 7 such as chromel wire is provided with a helieally wound portion 8 disposed at one end thereof, the pitch of the turns of the helix corresponding to the pitch of the threads of l the bolt to which the resistor is applied.

The diameter of the helix is such that the bolt may be screwed thereinto, as indicated in Fig. 1. Before the bolt is screwed into the helix of the resistor, a threaded nut 9 is placed upon the resistor in the position in dicated in Fig. 1. After the boltfi has been threaded into the helix, the nut 9, which is Serial No. 597,530.

provided with a threaded opening 10 having a pitch corresponding to that of the thread of the bolt and of sufficient diameter to screw upon the threads formed by the outer surfaces of the helix, is threaded upon the helix to a position shown in Fig 2. The nut- 9 serves both to securely clamp the helical portion of the resistor to the bolt and also to securely fasten the bolt to the terminal 4.

It will be seen that the construction provides a simple and inexpensive terminal device wherein a relatively large area of the resistor is securely clamped in intimate en gagement with the threads of the bolt and the nut. The portions of the resistor lying within the threads between the bolt and the nut are practically surrounded by metal and are protected from the gases and extreme temperatures prevailing within the furnace. This protection increases the life of the resistor at the point of connection, and perfect contact is secured between the terminal bolts and the resistor, thereby preventing the oxidization of the bolt to the nut with the consequential difficulties in detaching them after continued use in contact with furnace gases.

While my form of terminal device is par ticularly adapted for attaching resistor elements of heating furnaces to the furnace terminals, it will be understood that the device is equally effective for connecting any form of electrical conductor to any form of terminal in which a bolt-and-nut construction may be used.

While I have described and illustrated but one embodiment of my invention, it will be apparent to those skilled in the art that various changes, modifications, substitutions, additions and omissions may be made in the apparatus illustrated without departing from the spirt and scope thereof, as set forth in the appended claims.

I claim as my invention:

1. The combination with a threaded terminal member, of a conductor having a helically wound portion fitting the threads of the member and a threaded binding nut fitting the helically wound portion of the conductor for securing the conductor in conductive contact with the member.

2. The combination with a terminal memher and a threaded terminal bolt, of a con ductor having a heiically Wound portion fitto that of the threads and a threaded hind-- ting the threads of the bolt and a threaded ing nut fitting the heheaily wound portion binding nut fitting the helicall; wound porand having threads of a pitch corresoonding tion of the conductor for securing the bolt to that 01" the bolt and heiical portion of the to the terminal member and the conductor to conduetor. 15 the bolt. In testimony whereof. I have hereunto 3. The combination with a threaded tersubscribed my name this 17th day of ininal bolt, of a heiically Wound portion fit- October, 1922. ting the threads of the bolt and having the turns of the helix corresponding in pitch HOXVARD A. HANDS 

